(1) Field of the Invention
This invention relates to X-ray radiographic apparatus used in the medical field.
(2) Description of the Related Art
The X-ray radiographic apparatus used in the medical field may be classified, by the difference in images, broadly into an X-ray CT apparatus for photographing slice images of the body, and an ordinary X-ray radiographic apparatus, or what is known as a roentogenographic apparatus, for recording X-ray penetration images (planar images) of the body on X-ray film.
The X-ray CT apparatus causes an X-ray source to revolve around an examinee, and detects X-rays transmitted through the examinee. The detected X-rays are converted to a digital signal for image reconfiguration. The results are subjected to appropriate image processing such as enlargement or reduction to be shown on a monitor display. The examinee is transported on a horizontally movable bed to the apparatus.
The ordinary X-ray radiographic apparatus photographs an examinee lying on a bed, by means of an X-ray tube and X-ray film arranged vertically across the examinee. A different type of X-ray radiographic apparatus has, in place of the X-ray film, an image intensifier for converting X-rays to an optical image, and an X-ray television camera for picking up the optical image outputted from the image intensifier and converting the image to an electrical signal (video signal). The video signal is digitalized, and the result is subjected to appropriate image processing such as enlargement or reduction to be shown on a monitor display. A further type of X-ray radiographic apparatus has both the function to take photographs on film and the function to present pictures on a monitor display. These apparatus are collectively called hereinafter the ordinary X-ray radiographic apparatus.
While there is a physical difference between the images obtained from the X-ray CT apparatus and the ordinary X-ray radiographic apparatus, not a few components can be shared by the two types of apparatus which use the same principle of obtaining information about the body interior through X-ray exposure. Such components include the bed for supporting the examinee, a high voltage unit for supplying a high current to the X-ray tube to generate X-rays, an image processing unit for enlarging and reducing images shown on the monitor display, a console, and so on. The two types of apparatus are used for approximately the same purpose. Sometimes one patient is diagnosed by successively using the X-ray CT apparatus and ordinary X-ray radiographic apparatus.
However, the two apparatus are manufactured and sold separately as completely independent apparatus. In a medical organization having both apparatus, a large space must be secured to accommodate them at the same time or, as an alternative, a separate examination room must be secured to accommodate each apparatus. In the latter case, the patients diagnosed with the two apparatus must move from one examination room to the other. This imposes a considerable burden particularly on patients suffering from advanced diseases.